Summary The Schweizer 269C (300C) helicopter, registration C-GGUV, serial numberS1806, was being flown by an instructor and a student pilot at Hare Field, approximately 15nautical miles northwest of the Toronto/Buttonville Municipal airport in Ontario. They were on a training flight to practice autorotations with power-on recoveries in preparation for a flight test that was scheduled for the following week. After flying three uneventful straight-in autorotations, the student pilot entered a 360 autorotation from a height of approximately 800feet over the airfield. By half-way around the 360 turn, the airspeed was abnormally low, the rate of turn was slow, and the rate of descent was abnormally high. The instructor took control at a height of about 200feet and attempted to recover the autorotation. At that moment the airspeed was approximately 25knots indicated and rotor speed was about 400rpm. He lowered the nose to regain airspeed, then raised the nose as the helicopter approached the ground, but he did not consciously attempt to add power or bring in collective. The helicopter landed hard, striking on relatively soft turf in a slightly nose-up attitude. The heels of the skids struck first, causing them to spread. The helicopter then rolled forward and to the left, coming to rest inverted. It suffered substantial damage. The pilots received only minor injuries. There was no post-crash fire. Ce rapport est galement disponible en franais. Other Factual Information Silverline Helicopters Inc. is the operator of Hare Field, the location of the accident. Field elevation is 850feet above mean sea level (msl). There are two unlicenced turf runways, 06/24 and 03/21 and a licenced heliport1. The circuit altitude for helicopters is 1500to 1600feet msl, a height of 650to 750feet above ground level (agl)2, an altitude adopted in consideration of neighbouring property owners and local terrain. There are no written standard operating procedures (SOPs) covering airfield procedures. Silverline Helicopters Inc. is a flight training unit operating under PartIV of the Canadian Aviation Regulations (CARs). The syllabus for the flight training program is set out in the Company Flight Training Operational Directives as required by the CARs3. The CARs require flight training to be carried out in accordance with the applicable flight instructor guide and flight training manual or equivalent document . . . .4. The flight training manual5 is not presently available through Transport Canada (TC), but it will be available on the TC web site in the near future. The flight training manual is available from commercial sources and is used by Silverline Helicopters. The company does not have additional written SOPs for training syllabus exercises. The helicopter involved in the accident had been acquired new by Silverline in2000. At the time of the accident, it had approximately 200hours total time and records indicate that it had been maintained in accordance with regulations. There was no indication of any pre-existing mechanical failure or other condition of the helicopter that would have contributed to this accident. The instructor pilot on the accident flight had a commercial pilot - helicopter licence for just over two years and had approximately 800hours of helicopter experience. He had a classIV instructor rating for one year and had recently started instructing at Silverline. The student pilot was to be the first student to be recommended by him for a flight test. The student pilot had a student pilot permit - helicopter and approximately 80hours of helicopter flight time, all acquired during training at Silverline in the previous six months. The student had started his instruction with a different instructor, and 360 autorotations had been taught by the previous instructor. These had all been entered at 1000feet agl or higher. In the flight training manual, the 360 autorotation is part of exercise18, autorotations (range variations). It indicates that turns of 90, 180, or 360 may be used to reach a selected touchdown spot and that rates of descent in tight-turning autorotations can reach more than 2500feet per minute (fpm) in some types of helicopters. Speed reduction is an alternative method of reducing range. A chart shows a typical rate of descent of 2500-3000fpm at 25KIAS compared with a minimum of about 1600fpm at about 55KIAS. The flight training manual contains no guidance as to the height required to safely accomplish or practice these types of autorotation. It advises to abide by the height-velocity chart (which is presented in an earlier exercise on transitions) of the helicopter being flown and to regain the minimum rate of descent airspeed by 200feet agl in order to establish a normal autorotational touchdown profile. It provides a rule of thumb that 100feet of altitude is required for every 10knots of airspeed to be regained. The Transport Canada Flight Instructor Guide - Helicopter6, suggests an entry altitude of 1500feet agl to demonstrate the effect of speed variations to reduce or extend range in autorotations. There is no specific guidance as to minimum height for carrying out autorotations. It advises that airspeed should be increased to the minimum rate-of-descent speed before entering the shaded area of the height-velocity chart. The standards for helicopter flight tests for private and commercial licences7 require the candidate to carry out two types of autorotations, one of which will include a 180 turn. It calls for entry at a safe height but not lower than 500feet agl. There is no specific mention of a 360 autorotation. The Designated Flight Test Examiner Manual8 states that an engine failure should be simulated from a minimum of 1500feet above ground, but can be lower. It also indicates that autorotations usually consist of one straight-in and one 180 initiated at a safe height but in no instance less than 500feet agl. The aircraft flight manual9 emergency procedures for autorotation call for a glide speed of 52KIAS until initiating the flare at 50feet agl. The normal procedures for practice autorotation contain a warning to avoid airspeed and altitude combinations that are inside the height-velocity curve during power recovery. The height-velocity chart (AppendixA) states that operation is to be avoided in the shaded area, which is below 55KIAS at 150feet agl, and 50KIAS at 200feet agl, decreasing linearly to zero airspeed at 450feet. The occurrence flight was intended to be a brushup of the student's autorotations but was not a pre-test flight. There were no new exercises that would require a formal briefing. Consequently the briefing was abbreviated, covering only what was to be done, not how. Such a briefing is not considered abnormal under the circumstances. Weather at the time of the flight was good visual meteorological conditions (VMC). The surface wind was southwesterly at 5to 10knots with gusts in the vicinity reported as high as 20knots. Winds at circuit height were a bit stronger. After taking off at about 1245 eastern daylight time (EDT)10, the student performed three straight ahead autorotations from just above circuit altitude of 1500feet msl before commencing the 360 autorotation. The student allowed the altitude to climb to 1600or 1700feet before entering the 360 autorotation. Initial entry into the autorotation was normal. By the 180 point, the autorotation was not progressing ideally, but the instructor decided not to intervene because intervention by an examiner would constitute failure on a flight test. The student believed that the instructor would take control when and where required to accomplish the learning objective and continued the exercise. When he took control, the instructor doubted that a power recovery was feasible from that flight condition. Therefore he continued with the autorotation, intending a power recovery in the flare. He aggressively lowered the nose to a steep nose-down attitude, then almost immediately raised the nose using cyclic in order to land flat. He did not introduce power or raise the collective. Personnel on the airfield responded to assist in the rescue. The instructor and student were both taken to hospital, treated and released. The student, who was not wearing a helmet, was treated for minor facial cuts. The instructor was wearing a helmet which was undamaged except for some superficial scratches.